Balanced slide-valve



(No Model.) 4 Sheets-Sheet 3.

T. TRIPP. BALANGED SLIDE VALVE.

No. 470,339., Patented Mar. 8, 1892.

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T. TRIPP. BALANCED SLIDE VALVE.

No. 470.339. Patented. Mar. -8. 1892..

WITNESSES:

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THOMAS TRIPP, OF AVON, MASSACHUSETTS.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 470,339, dated March 8,1892..

Application filed June 3, 1889. serial No. 312,961. (No model.)

To all whom 'it may concern.-

Be it known that I, THOMAS TRIPP, a citizen of the United States,residing at Avon, in the county of Norfolk and State of Massachusetts,have invented a new and useful Balanced Slide-Valve, of which thefollowing is a specification.

My invention relates to valves designed for use on engines, especiallyof the locomotive class; audit has for its object the production ofacompound balanced valve possessing the following special advantageswhen applied to the present style of locomotive: It can be readilybolted to the common valve-seat and inclosed by the usual steam-chest.It is balanced, and any excessive pressure within the steam-cylinder iseffectively relieved into the exhaust-port. It will on the short travelof the valve, when a locomotive is running at high speed, present aboutdouble the area of port for admission and exhaust compared with thecommon slide or piston valve. It is also easilymanufactured and is verydurable.

All the advantages possessed by the valve in its operation would be thesame whether applied to a locomotive-engine or any other class ofengines.

Figure 1 represents valve-chamber in front elevation. Fig. 2 representsvalve-chamber in side elevation. Fig. 3 is a cross-sectional view ofvalve-chamber on line 30 30 of Fig. 2. Fig. 4 is a central sectionalview of valvechamber on line 31 31 of Fig. 1. Fig. 5 is across-sectional view of valve-chamber on line 32 32 of Fig.2. Fig.6represents valve-chamber in side elevation with relief-plates removed.Fig. 7 represents bottom plate for valve-chamberin plan, and Fig.8 is acentral cross-section of same on line 33 33. Fig. 9 represents valve infront elevation. Fig. 10 represents valve in side elevation. Fig. 11 isa cross-sectional view of valve on line 34 34 of Fig. 10. Fig. 12 is acentral sectional view of valve on line 35 35 of Fig. 9. Fig. 13represents center packing-piece in front elevation, and Fig. 14 is aplan of same. Fig. 15 represents side packing-piece in front elevation,and Fig. 16 is a plan of same. Fig. 17 represents back valve-head infront elevation. Fig. 18 represents back valve-head in side elevation.Fig. 19 represents back valvehead in inverted plan. Fig. 20 isacross-sectional view of back valve-head on line 36 36 of Fig. 18. Fig.21 is a sectional view of back valve-head on line 37 37 of Fig. 17. Fig.22 represents, in front elevation, a modified form of packing which maybe used in the valve-heads, and Fig. 23 is a side elevation of same.Fig. 24 represents valve-chamber in central longitudinal section andvalve in side elevation as applied to a locomotive-cylinder, which isrepresented in central longitudinal section. Fig. 25 is a full sectionalview of valve-chamber and cylinder on line 38 38 of Fig. 24,representing the valve in plan.

In the drawings, Figs. 24 and 25, the following are all of a commontype: cylinder 40, having front head 41, back head 42, supplyports 43and 43", admission-ports 44 and 44", exhaust-port 45, and provided withvalve-seat 46, piston 47 and piston-rod 4S, steam-chest 49, andsteam-chest cover 50.

All the parts composing the valve-chamber and valve are preferably madeof cast-iron, except the steel rods; but they may be made of anysuitable material.

In order to obtain a satisfactory balanced valve for use especially uponlocomotives, piston-valves have been used; but by experiment and inpractical use, using an indicator, it has been found that forlocomotives running at high speeds the piston-valve, restricted in itsdiameter by the height of the usual steam-chest, could not let steameither into or out of the cylinder quick enough. To remedy thisdifliculty, piston-valves of larger diameter might be used if it werenot for the fact that the height of the ordinary steam-chest would notpermit of any such increase in diameter. Other difficulties areencountered when piston-valves of large diameters are used, such asunwieldiness of proportions and largely-increased steam-clearance. Forlocomotives running at low speeds for freight service it has beenpractically demonstrated by use of indicator that the ordinarypistonvalve is quite effective and fairly sufficient.

My valve can be located within the steamchest of any ordinarylocomotive. It is balanced. The steam-clearance is practically the sameas if a common slide-valve were used, and with the valve at a length oftravel such as would be used when a locomotive is running at high speedthe area of port-opening would be about double that presented by thecommon slide-valve. These advantages are of great economic importanceand value.

The valve-chamber or cage 51 consists of the bottom plate 52, thecircular case 53, the relief-plates 54 and 54, and the relief-plateguides and stops 55 and 55.

The bottom plate for the valve-cha1nber is represented in plan andcentral crosssection by Figs. 7 and 8, respectively, and is constructedas follows: It is provided with the two lips 56 and 56', which lap overthe ends of the valve-seat 46 of the cylinder 40, thereby preventing anyendwise movement of the plate upon the valve-seat. The' superficial areaof the plate between said lips is substantially the same as that of thevalve-seat 46. The admission-ports 57 and 57' each have the same area ofopening and coincide with the admission-ports li and 4t, respectively,of the cylinder. The exhaust-ports 58 have the same area of opening lessthe area of the bridge 59 and coincide with the exhaust-port 45 of thecylinder. The object of the bridge is when the valve is disconnected toprevent the valve-packings from catching in the exhaust-ports 58, thewidth either of which is greater than the width of the valvepackings.The plate is fastened to the circular case by means of the screws 60.The bottom plate is used mainly as a mechanical convenience in themanufacture, application, and use of the valve. It is obvious that,except for the reasons stated, especially when the valve is applied toan engine constructed to receive the valve, the circular case may bebolted directly to the cylinder without the intervention of the bottomplate.

The circular case 53 is provided with the following: the main bore inwhich the valve reciprocates, which consists of the space between thecircular line 61 and the top of the bottom plate 52, supplemental ports62 and 62', relief-ports 63 63' and 64 and 64, relief-ports 65 and 65',seats for relief-plates 66 and 66, relief-plates 54 and 54, and reliefguides and stops 55 and 55, exhaust-relieving cuts 67 and 67', and bolts68. It will be noticed that the width of the space over which the valvetravels is less than the length of the admissionports. The result ofthis difference is that the supplemental ports 62 and 62 have an openconnection directly with the admissionports 57 and 57, respectively, andthis connection is not interfered with either by the presence or travelof the valve. T ie reliefports 63 and 63' extend from the seats 66 and66, respectively, to the supplemental port 62, and in a like manner therelief-ports 64 and 64. extend from the seats 66 and 66', respectively,to the supplemental port 62. The relief-ports 65 and 65' extend from theseats 66 and 66', respectively, into the space within the valve-chamberdirectly over the exhaust-ports 58. The seat 66 is covered by therelief-plate 54, which is guided in its lifting movement by the tongue69, which slides in the opening which the cotter 72' passes.

of the guide and stop 55. The length of the opening 70 is greater thanthe length of the tongue, so that the uneven lifting of the relief-platewill not bind the tongue in the guide, as the tongue is provided with aslot 71, through which the cotter 72 is passed, which is fastened to theguide. The tongue is pivoted, so far as its endwise movement isconcerned, on the cotter. In like manner the seat 66 is covered by therelief-plate 54, which plate is provided with the tongue 69, whichslides in the opening 70, the tongue being provided with the slot 71',through The bolts 68, which secure the valve-chamber to the valveseat 46of the cylinder, are provided with the extension-bolts 73, to which therelief-plates, guides, and stops 55 and 55' are secured by means of thenuts 74.

The valve 75 is provided with the back head 76 and front head 76, whichare fastened together by the stay-rods 77 and 77. The back head isprovided with the usual valve-rod 78, with this exception, the heads arealike. The back head 76 is constructed as follows: It is provided with acircular packing composed of the three pieces 79, 80, and 80. Thepacking-piece 79 (represented in elevation and plan by Figs. 13 and 14,respectively) is provided with a flange 81 and the two lips 82 and 82.The packing-piece 80 is provided with the center piece 83 and the twoflanges 84 and 8t, and the packing-piece 81' is in a like mannerprovided with the center piece 83' and the two flanges 8t" and 84/. Thepacking is assembled within the head, and is held in its outwardposition by means of the spiral springs 85. To the lower face of thehead are fastened the packing locking-pieces 86 and 86', which aresecurely pinned to the head by means of pins 87 and 87 respectively. Ina like manner a front head 76' is provided with the packing-piece 79,the packing-pieces 80 and 80", and the locking-pieces 86 and 86/!!- Themodified form of packing represented in front elevation and sideelevation by Figs. 22 and 23, respectively, which may be used instead ofthe packings described and shown, consists of the three pieces 88, 89,and 89, the joint between the pieces 88 and 89' being protected by thetongue 90, which is pinned to the piece 89'. The joint between thepieces 88 and S9 is protected in the same manner.

The operation of my valve is as follows: It is obvious that the-valve isas perfectly balanced as if it were an ordinary piston-valve, for thereason that all the pressures against the valve are counterbalanced inthe same manner as if a piston-valve were used. The

operation of the flat sliding face of the valve in ad mit-ting andexhausting the steam into and from the cylinder is the same as ifacommon D slide-valve were used; but it will be noticed that, aspreviously stated, the length of each admission-port is greater than thelength of the flat sliding face of the valve.

IIO

The same is true relative to the exhaust-port. Both admission-ports arethe same, therefore, if I assume the size of one of the admissionportsto be fifteen inches long by one and one-fourth inches wide. A plain Dslide-valve on a locomotive at high speed, the valve arranged (as isusual) to cut off the steam at six inches stroke of the piston withinthe cylinder, would open the admission-port about five thirty-seconds ofone inch, which would give an area of opening for the admission of steamof about two and one-fourth square inches. The same opening would bepresented for the exhausting of the steam. Now if one of my valves isused over an admission-port of the same size namedfifteen by one andone-fourth inches-the valve having alength of face of thirteen inches,the opening presented for the admission of steam into the cylinder wouldhave an area of four and one-half square inches that is to say, it wouldpresent an opening for admission twice as large as a plain D slidevalvewould presentand my valve would present the same area of opening for theexhaust as it would for admission of steam. This great and extremelyvaluable increase of opening is obtained as follows: The admission-portbeing fifteen inches long and the length of valveface being thirteeninches, there will be left on each side of the valve-face an opening oneinch long by one and one-fourth inches wide. Therefore the two openingswould have an area of two and one half square inches. These openingsform a part of the supplemental 'port, which extends entirely around thecircular portion of the valve. Therefore the area presented foradmissionby a five thirty-seconds of an inch movement of the valve would be thelength of the face of the valve, or thirteen inches, multiplied by fivethirty-seconds of an inch, equals 1.93 square inches, plus the length ofthe circular face of the valve, or sixteen and three-fourths inches,multiplied by five thirty-seconds of an inch, equals 2.61 square inches,and 1.93 plus 2.61 equals about four and one-half inches.

The steam-clearance inside the valve-chamber is about one-tenth that ofa valvechamber designed to receive an ordinary pistonvalve.

The valve being balanced, any excessive pressure within the cylindershould be relieved by the use of relief-plates. If it is assumed thatthe piston and valve are moving in lines, as indicated by arrows in Fig.24, an excessive pressure may be created sufficient to blow outthe-front cylinder-head 41; but the relief-ports, as described andshown, would entirely relieve the cylinder from injurious pressure, asindicated by arrows, in the following manner: Any pressure Within thecylinder between the piston and front head 41 would lift therelief-plates, for the reason that the relief-ports 63 and 63 are alwaysin. direct communication "with the cylinder through supplemental port 62and admission-ports 57 and 44. The lifting of the relief-plates wouldlocking-pieces and the circular packing, said packing being composed ofthree pieces, one of said pieces having a center flange and twoprojecting side lips and each of the other pieces having a center pieceand two side flanges, in combination with the valve-chamber having thesupplemental ports, which extend around the interior of the circularcase and partially around the valve, substantially as and for thepurpose set forth.

- 2. The valve-chamber having the circular case, which is provided withthe supplemental ports, which extend around. the interior of thecircular case opposite the admission-ports and having the bottom plate,which is provided with admission and exhaust ports, in combination withthe valve having two heads fastened together, each of said heads beingprovided with a circular packing and lockingpiece, substantially asdescribed.

3. The valve-chamber provided with the supplemental ports, which extendaround the interior of the circular case opposite the admission-ports,relief-ports, relief-plates, and relief-plate guides and stops, incombinat on with the valve having two heads, each of which is providedwith the locking-pieces and the circular packing, saidpackingbeingcomposed of three pieces, one of said pieces having a centerflange and two projecting side lips and each of the other pieces havinga center piece and two side flanges, substantially as and for thepurpose set forth;

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

THOMAS TRIPP.

WVitnesses:

JAMES A. WooDBURY, E. FRANK WOODBURY.

